Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Que jogadores jogam como guarda?
 ###Tabelas: CREATE TABLE reserves___academy (reserves___academy_id AUTO_INCREMENT PRIMARY KEY, Exit Date VARCHAR, Pos. VARCHAR, Player VARCHAR, To club VARCHAR, Transfer fee VARCHAR) CREATE TABLE uk_ratings (uk_ratings_id AUTO_INCREMENT PRIMARY KEY, Episode number INT, Title VARCHAR, Original airing on Channel 4 VARCHAR, Time of airing on Channel 4 VARCHAR, Total viewers and Rank on C4 VARCHAR, Total viewers VARCHAR) CREATE TABLE d (d_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, No. INT, Nationality VARCHAR, Position VARCHAR, Years for Grizzlies VARCHAR, School/Club Team VARCHAR) CREATE TABLE frequency_specifications (frequency_specifications_id AUTO_INCREMENT PRIMARY KEY, HyperTransport version INT, Year INT, Max. HT frequency VARCHAR, Max. link width VARCHAR, Max. aggregate bandwidth (bi-directional) VARCHAR, Max. bandwidth at 16-bit unidirectional VARCHAR, Max. bandwidth at 32-bit unidirectional* VARCHAR) CREATE TABLE women's_doubles_111 (women's_doubles_111_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament Name VARCHAR, Location VARCHAR, Partner VARCHAR, Score in Final VARCHAR)  
SELECT Player FROM d WHERE Position = Guard